Converter circuits are pervasive in many electronic applications from computers to automobiles, for example. A common application for voltage and/or converter circuits is in power supply systems. Generally, voltages within a power supply system are generated by performing a DC-DC, DC-AC, and/or AC-DC conversion by operating a switch loaded with an inductor or transformer as a converter circuit. One class of such systems includes switched mode power supplies (SMPS). An SMPS is usually more efficient than other types of power conversion systems because power conversion is performed by controlled charging and discharging of the inductor or transformer and reduces energy lost due to power dissipation across resistive voltage drops.
Switching converter circuits that may be used for an SMPS may include buck converters, boost converters, flyback converters, half bridge converters, and full bridge converters, among others. Both buck and boost converters typically make use of an inductor whereas a flyback converter isolates a load and may multiply the voltage conversion ratio through the use of a transformer. Half bridge converters often use two transistors coupled to an inductor at an intermediate node between the switching transistors and full bridge converters often use four switching transistors. Another type of converter is a dual half bridge series converter, which includes two half bridge converter circuits coupled in series with an energy storage element, such as an inductor, coupled between the two half bridge converters.
In many switched-mode power converters, the timing of the switches is determined by a feedback control system in order to control an output voltage and/or current characteristic of the power supply. For example, a feedback controller may compare a measured output voltage of a power supply with a voltage reference to produce an error signal, and then use the error signal to adjust a duty cycle of a pulse-width modulator circuit that determines switching signals.